PURPOSES : In this study, we evaluated the quality levels of abrasion resistance and freeze-thaw resistance to the surface layer (colored layer) by using an overseas abrasion resistance test method to confirm the quality suitability of the concrete block surface for a domestic production permeable block. METHODS : In this study, a new evaluation item for increased durability apart from the quality standard of the permeable block was considered, namely, evaluation of the durability of the surface layer and the freeze-thaw resistance of the permeable block itself by EN 1338, ASTM C 779, 994, and GR 4009 (KS F 4419). RESULTS : The abrasion resistance test for the permeable block revealed that there were relative differences according to the different test methods. However, it was observed that if the ASTM C 779 test results did not meet the wear resistance quality standards, it did not satisfy ASTM C 944 and EN 1338. The ASTM C 779 test result was analyzed to have the highest objectivity and discernment, and this test method was proposed as a permeable block wear test method. In addition, the freeze-thaw resistance test method by the GR 4007 standard can be measured by strength, so it is possible to evaluate the resistance of the permeable block through this test method. CONCLUSIONS : The abrasion resistance test and freeze-thaw resistance test can contribute to the improvement of the permeable block when added to the current quality evaluation tests.

올레핀은 석유화학산업에서 대부분의 물질의 근간이 되는 핵심적인 물질이며 특히 고분자 합성에 있어 매우 중요하다. 이러한 올레핀 물질을 효율적으로 분리/가공하는 공정은 산업발전에 있어 지대한 영향을 끼친다. 본 연구에서는 올레핀 물질 중 프로필렌 기체를 선택적으로 분리하는 고분자 복합막을 제조하여 투과 및 선택 성능을 증대시키고자 고투과성 매질 인 poly(1-trimethylsilyl-1-propyne) (PTMSP)에 양친성 고분자를 이용하여 개질하였다. 또한 올레핀 분자와 상호작용이 있는 AgBF4 염 및 촉진수송을 극대화 시키기 위하여 이온성 액체인 EMIM-BF4를 첨가하여 올레핀/질소 투과 분리 성능을 향상시 켰다. 기존 PTMSP 복합막의 경우 굉장히 높은 자유부피를 가져 높은 기체 투과성능을 보이는 반면 투과시키고자 하는 기체에 대한 선택적인 분리 성능이 매우 떨어져 낮은 선택도를 보인다. 이를 극복하고자 양친성 고분자를 PTMSP 계면에 그래프트 공중합을 시켰으며 올레핀과 높은 상호작용을 보이는 AgBF4 염 및 EMIM-BF4 이온성 액체를 첨가하여 프로필렌/질소에 대한 선택도를 향상시켰다.

염료감응형 태양전지는 지속 가능한 에너지원으로서 많은 관심을 받고 있다. 염료감응형 태양전지의 효율과 장기 안정성은 전극 물질과 전해질에 의해 크게 영향을 받는데 본 총설에서는 전해질에 초점을 두어 서술하고자 한다. 고분자 전해질막은 염료감응형 태양전지에서 기존의 액체 전해질을 대체하기 위한 대안으로 제시되어 왔다. 기존의 액체 전해질은 높 은 효율을 나타낼 수 있지만 장기적인 안정성 문제와 누액 문제로 인해 고분자 전해질막에 관한 관심은 지속적으로 증가하고 있으며 매년 이와 관련된 논문들이 활발히 보고되고 있다. 본 총설은 염료감응형 태양전지를 위한 고분자 전해질막의 개념과 개발에 대한 간단한 설명을 다루고 있으며 고분자 매트릭스의 개질, 유-무기 가소제 및 이온성 액체와 같은 첨가제의 도입에 따른 염료감응형 태양전지의 효율과 전기화학적 특성에 대해서도 최근의 연구들이 정리되어 있다.

본 연구에서는 titanium nitride (TiN) 나노 섬유와 poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOTPSS) 전도성 고분자로 이루어진 전극과 poly(vinyl alcohol) (PVA) 기반 고분자 전해질 분리막을 이용하여 슈퍼 캐퍼시터를 제조하였다. TiN 나노 섬유의 경우 높은 전기 전도도와 이차원적 구조로 인한 스케폴드 효과를 기대할 수 있다는 점에서 전극 물질로 사용되었다. PEDOT-PSS 전도성 고분자는 수소 이온과 산화-환원 반응을 통해 보다 높은 정전용량을 나타낼 수 있으며 용액상에 분산이 용이해 유무기 복합제를 형성하기에 적합하였다. PVA 기반의 고분자 전해질 분리막은 기존의 액상의 전해질의 문제인 외부 충격에 대한 안정성을 확보할 수 있으며 염으로 사용된 H3PO4의 경우 수소 이온은 빠른 확산으로 인해 캐퍼시터의 충방전 효율에 이점이 있다. 본 연구에서 보고된 PEDOT-PSS/TiN 슈퍼캐퍼시터의 정전용량은 약 75 F/g으로 기존의 탄소기반 캐퍼시터에 비해 큰 폭으로 증가한 값이다.

Recycling of drained nutrient solution in hydroponic cultivation of horticultural crops is important in the conservation of the water resources, reduction of production costs and prevention of environmental contamination. Objective of this research was to obtain the fundamental data for the development of a recirculation system of hydroponic solution in semi-forcing cultivation of ‘Bonus’ tomato. To achieve the objective, tomato plants were cultivated for 110 days and the contents of inorganic elements in plant, supplied and drained nutrient solution were analyzed when crop growth were in the flowering stage of 2nd to 8th fruiting nodes. The T-N content of the plants based on above-ground tissue were 4.1% at the flowering stage of 2nd fruiting nodes (just after transplanting), and gradually get lowered to 3.9% at the flowering stage of 8th fruiting nodes. The tissue P contents were also high in very early stage of growth and development and were maintained to similar contents in the flowering stage of 3rd to 7th fruiting nodes, but were lowed in 8th node stages. The tissue Ca, Mg and Na contents in early growth stages were lower than late growth stages and the contents showed tendencies to rise as plants grew. The concentration differences of supplied nutrient solution and drained solution in NO3-N, P, K, Ca, and Mg were not significant until 5 weeks after transplanting, but the concentration of those elements in drained solution rose gradually and maintained higher than those in supplied solution. The concentrations of B, Fe, and Na in drained solution were slightly higher in the early stages of growth and development and were significantly higher in the mid to late stages of growth than those in supplied solution. The above results would be used as a fundamental data for the correction in the inorganic element concentrations of drained solution for semi-forcing hydroponic cultivation of tomato.

In this study, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT-PSS) was introduced into polymer gas separation membrane. The mixed matrix membrane composed of poly(2-[3-(2H-benzotriazol –2-yl)-4-hydroxyphenyl] ethyl methacrylate)-poly(oxyethylene methacryalate) (PBEM-POEM) comb copolymer matrix and PEDOT-PSS filler. Incorporation of PBEM-POEM makes isolated PEDOT-PSS chain transform into a fiber-like interconnected structure due to hydrogen bonding interaction. This structure could act as a facilitated pathway for enhancing gas diffusivity through the membrane. The best performance of prepared PEDOT-PSS/PBEM-POEM composite membranes was CO2 permeability of 59.6 Barrer with a CO2/N2 selectivity of 77.4, being close to the 2008 Robeson upper bound.

We fabricated dual-phase free-standing polymeric membrane for high performance CO2/N2 separation, introducing amphiphilic, CO2-philic copolymer via one-step free radical polymerization, or (2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl methacrylate)-graft-poly(oxyethylene methacrylate) (PBE). PBE filler partially interacts with Pebax polymer matrix to generate the interconnected CO2 philic network, exhibiting a microphase-separated, or dual-phase behavior in Pebax matrix. The performance of CO2/N2 separation was increased according to the PBE content, with the maximum selectivity at 5 wt%. The enhancement of Pebax/PBE CO2-philic membrane was attributed to the formation of CO2-philic channel consisting of ether oxygens and triazole groups. The best performance was CO2 permeability of 175.3 Barrer and CO2/N2 selectivity of 48.2.

해수담수화의 성장과 함께 붕소 제거를 위해서 많은 연구가 진행되고 있다. 흡착제, 이온교환수지 등 많은 방법으로 붕소가 제거되고 있는데, 그 중에서 분리막을 이용하여 제거하는 기술은 높은 선택성과 효율로 인해 빠른 성장을 보이고 있는 기술 중에 하나이다. 붕소 제거는 여러 분리막 중에서 역삼투막이 많이 사용되는데, m-phenylenediamine (MPD)와 trimesoyl chloride (TMC)를 이용한 역삼투막 제조가 현재 가장 많이 사용되는 기술이다. MPD와 TMC를 이용하여 Polysulfone 지지체 위에 polyamide 활성층을 제조하는데, 이를 통해 높은 수투과량과 염제거율을 얻을 수 있다. 본 연구에서는 polyamide 활성층에 표면개질을 이용하여 염제거율 및 보론 제거율을 증가시킬 것이다.

본 연구의 목적은 위성의 밝기온도를 기반으로 한 정량적 강우량 추정기법의 개선을 위함이다. 우리나라 여름철 강우사례를 이용하여 강우추정을 위한 비선형 관계식을 개선하였다. 분석을 위해 레이더 자료로 기상청 기상레이더 관측망의 고도 1.5 km와 CMAX 반사도 합성자료를 사용하였으며, 위성자료는 천리안 위성의 가시, 적외, 수증기 채널의 자료를 이용하였다. 새롭게 도출된 알고리즘은 A-E method, CRR v4.0 analytic function의 결과와 비교를 하였다. 검증을 위해 우리나라 ASOS에서 관측한 지상강우량 자료를 사용하였다. 공간검증을 위해 검증지수로 POD, FAR, CSI를 계산하였으며 각각 0.67, 0.76, 0.21로 나타났다. 정량적 강우검증을 위해 MAE와 RMSE를 계산하였으며 각각 2.49, 6.18 mm/h였다. A-E에 비하여 정량적인 오차가 줄어들었으며 CRR에 비하여 공간적인 정확도가 증가하였다. 개선한 관계식을 적용한 방법이 두 알고리즘의 부족한 부분을 보완할 수 있는 것으로 판단된다. 개선한 관계식을 통해 강우를 추정하는 방법은 복잡한 알고리즘을 거치지 않고 짧은 시간에 강우추정이 가능함으로써 현업용 실시간 초단기 예보에 활용될 수 있다.

해수담수화의 빠른 증가와 함께 붕소 제거에 대한 중요성이 상승하고 있다. 본 연구는 표면개질 시 친수성 화합물을 이용하여 수투과량을 최대한 막고 붕소 제거율을 높이기 위한 연구를 진행하였다. 첫째로, Control polyamide 역삼투막을 얻기 위해 M-phenylenediamine (MPD)와 trimesoyl chloride (TMC)를 Polysulfone 한외여과막에 계면중합을 시켜 polyamide 활성층을 제조하였다. 다음으로, Control polyamide 역삼투막에 표면개질을 진행시켜 D-gluconic acid (DGCA)와 D-gluconic acid sodium salt (DGCA-Na)를 glutaraldehyde (GA)와 hydrochloric acid (HCl)을 이용하여 합성시켰다. 합성된 역삼투막의 표면 분석을 위해 XPS 분석을 진행하였으며, DGCA 및 DGCA-Na 화합물과의 반응이 되었음을 확인하였다. 또한, morphology 측정을 위해 FE-SEM과 AFM 분석을 진행하였으며, polyamide 활성층 형성 및 표면 거칠기를 확인할 수 있었다. 수투과량의 경우, 표면개질을 진행한 역삼투막은 10 GFD 수준이거나 그 이하의 값을 가졌다. 하지만, DGCA 및 DGCA-Na 화합물과 표면개질을 진행한 역삼투막의 붕소 제거율은 94.38, 94.64%로, Control polyamide 역삼투막보다 각각 12.03, 12.29 %p만큼 큰 값을 가지는 것을 확인할 수 있었다.

Three kinds of STS304-Zr alloys were fabricated by varying the Zr content, and their microstructure and fracture properties were analyzed. Moreover, we performed heat treatment to improve their properties and studied their microstructure and fracture properties. The microstructure of the STS304-Zr alloys before and after the heat treatment process consisted of α-Fe and intermetallics: Zr(Cr, Ni, Fe)2 and Zr6Fe23. The volume fraction of the intermetallics increased with an increasing Zr content. The 11Zr specimen exhibited the lowest hardness and fine dimples and cleavage facets in a fractured surface. The 15Zr specimen had high hardness and fine cleavage facets. The 19Zr specimen had the highest hardness and large cleavage facets. After the heat treatment process, the intermetallics were spheroidized and their volume fraction increased. In addition, the specimens after the heat treatment process, the Laves phase (Zr(Cr, Ni, Fe) 2) decreased, the Zr6Fe23 phase increased and the Ni concentration in the intermetallics decreased. The hardness of all the specimens after the heat treatment process decreased because of the dislocations and residual stresses in α-Fe, and the fine lamellar shaped eutectic microstructures changed into large α-Fe and spheroidized intermetallics. The cleavage facet size increased because of the decomposition of the fine lamellarshaped eutectic microstructures and the increase in spheroidized intermetallics.

급진적인 산업발전에 따른 무분별한 이산화탄소 배출로 인하여 지구온난화, 이상 기후 등의 문제가 불거지고 있으며 이는 한 나라에만 국한되지 않은 국제적인 문제가 되었다. 위와 같은 문제를 해결하고자 본 연구에서는 이산화탄소에 대해 높은 친화도를 가지고 있는 PEGBEM-g-POEM 가지형 공중합체를 합성하였으며 CaCO3염을 첨가하여 염의 중량에 따 른 혼합매질분리막의 이산화탄소/질소 투과 성능을 관찰하였다. CaCO3염이 고분자 중량 대비 50% 첨가되었을 때 최적의 이 산화탄소/질소 분리 투과성능을 보였으며, 선택도는 염을 추가하기 전 44.7에서 45.42로 크게 변하지 않은 반면 이산화탄소 투과도는 염을 첨가하기 전 22.5 GPU에서 28.16 GPU로 약 25% 향상되었다. 이는 첨가한 염과 이산화탄소간의 상호작용으 로 인하여 향상된 고분자 복합막의 이산화탄소에 대한 용해도에 기인하는 것으로 생각된다. 또한 염을 과량으로 첨가한 경우 에는 고분자가 복합막의 표면을 충분히 메우지 못하여 계면결함이 생성되었으며 이로 인해 이산화탄소 기체 분리성능이 감소하였다. 기체분리성능 향상을 위해서는 적정량의 염 첨가가 필수적인 것으로 분석되었다.

This experiment was carried out to determine the effect of organic fertilizer and seed mixture on productivity, botanical composition and forage quality in middle areas(Geumsan, 250m sea level) pasture. Total six experimental pastures (orchardgrass, timothy and tall fescue based seed mixture and with or without organic fertilizer) were established in autumn, 2014 and evaluated productivity and agronomic characteristics from 2015 to 2016. Plant heigh was higher in orchardgrass based mixture and orchardgrass and tall fescue based mixture were higher in 2nd harvest. There was not found the significant difference among treatment(P<0.05) in dry matter (DM) content. Botanical composition in 1st harvest was higher weed portion in orchardgrass based mixture and legumes was disappeared at 3rd harvest in all treatments. Fresh and dry matter yield was higher in 2nd year than 1st year. In 1st year, orchardgrass based mixture with organic fertilizer plot was the highest(P<0.05) DM yield, but tall fescue based mixture with organic fertilizer was the highest in 2nd year. Content of crude protein (CP) was the highest in tall fescue based mixture and Timothy based mixture showed low in ADF (acid detergent fiber) and NDF (neutral detergent fiber) content. But the content if in virto dry matter digestibility was higher than others. In 2nd year, the nutritive value of 2nd and 4th harvested grasses were higher and average RFV (relative feed value) value was the highest at 4th harvest. According to this result, orchardgrass and tall fescue based mixture would be recommendable for farm who considering productivity and timothy based mixture would be recommendable for considering forage quality in middle areas of Korea.

PURPOSES : Road sectors contribute approximately 16 % of total GHG emission rates in South Korea. Engineers and experts expend significant efforts to identify countermeasures for the reduction of carbon emission. This study aims to determine how total carbon emission rates change depending on whether or not there is speed limit enforcement.METHODS: In this study, Lamm’s travel speed profile theory is first adopted to select the hazard road, which sections are designated as speed limit enforcement. Second, Motor Vehicle Emission Simulator (MOVES) was used to simulate the carbon emission on the road.RESULTS : The total carbon emission rate under speed limit enforcement was 10,773 g higher than the condition without speed limit enforcement in the designated road. This might affect acceleration, which can lead to increased emissions.CONCLUSIONS : There would be no researches about proving the relationship how speed limit enforcement has an effect on carbon emission. The result of our study can provide valuable guidelines regarding road safety and eco-friendly roads.

PURPOSES: This research aims to estimate the occurrence of hydroplaning on roads based on the road alignment types and rainfall intensity in Seoul.METHODS: Three types of data were used for estimation of hydroplaning in this study. The Inner Circulation Road (12.5 km) to the Bukbu Expressway (7.4 km) in Seoul was selected as the test road and data was collected for road information using a probe-vehicle. Precipitation was observed from Automatic Weather System in Seoul. These data were interpolated by applying Inverse Distance Weighted Methodology for hydroplaning estimation. Finally, the water depth information of the roads was observed using an RCM411 device.RESULTS : This study demonstrated that the cross slope with small-angle-tilt or vertical section with large-angle-tilt are the primary factors causing hydroplaning on the roads. The flow velocity on steep slope is high; however, large drainage lengths result in hydroplaning on the roads.CONCLUSIONS : This result can contribute towards the reduction of car accidents on rainy days. Furthermore, information regarding hydroplaning can be delivered to drivers more rapidly and precisely in the future.

We present a facile, room temperature synthesis of poly(ethylenealt- maleic anhydride)-graft-poly(propylene glycol) (PEMA-g-PPG) graft copolymer-based CO2/N2 gas separation membrane with 100% conversion reaction without any further purification process. As confirmed by the Fourier transform infrared (FT-IR) and nuclear magnetic resonance (1H NMR) spectroscopy, the PEMA-g-PPG was successfully synthesized with 100% conversion of PEMA and PPG monomers. It was confirmed that the PEMA-g-PPG was amorphous and rubbery state according to the X-ray diffraction (XRD) and differential scanning calorimetry (DSC0 results. Therefore, PEMA-g-PPG/polysufulfone composite membrane exhibited high performance of CO2 permeability (99.1 Barrer) and selectivity (82.6 for CO2/N2 and 26.8 for CO2/CH4), surpassing conventional PEBAX block copolymer membrane.